Chapter 20 of Hell's Paradise: Jigokuraku.
Shion gives Tensa and Nurugai an opportunity to run from the mystery man. After getting far away from the man, Tensa introduces Nurugai to his master, Yamada Asaemon Shion. Shion scolds Tensa for using only his speed in his swordplay against his opponent. He then tells them that after executing Akaginu for trying to seduce him, he had found a current that could lead them away from the island, however, he pointed out that he sensed an unfamiliar presence. Tensa says that the three of them should go to the spot but Shion raises his sword and asked why he was helping his criminal. Tensa explains that she was innocent but Shion finds this as no excuse to ignore his duties as a Yamada Asaemon. Tensa persuades Shion by reminding him of the time he saved him off of the streets and says that he wanted to do the same for her. Shion is convinced and allows Tensa to do as he please. Nurugai greets Shion by calling him sensei but Shion says that she didn't need to call him by this title since he had not taught her anything. Before they could go to the current Shion discovered, Shion warns them that they should take caution of the mysterious being that they faced. However, it instantly appears behind Tensa and Nurugai as a female, saying that they underestimate her. Shion moves the two out of the way but has his throat cut by the female. Tensa fights back but the female states that she has already gotten used to his swordplay and deals a devastating blow to Tensa.